Conformational and supramolecular properties of main chain and cyclic click oligotriazoles and polytriazoles

Abstract

This Feature Article gives a summary on the conformational and supramolecular properties of a special type of click molecules, namely, main chain and cyclic oligo- and polytriazoles. The triazole ring is an interesting structural motif since it is a hydrogen bond donor and acceptor, a large molecular dipole and also a metal ligand. It can interact with a wide variety of functionalities, e.g. hydrogen bonding partners (e.g. amides or anions), molecular dipoles, and metal ions to generate many fascinating conformational features such as pseudo rod-like, U-turn, helical, double helical structures, beta-strands and beta-sheets. Oligo- and polytriazoles can also exhibit interesting supramolecular attributes such as host-guest complexation, self assembly, chemosensing and gelating properties. It is believed that many new and unique conformational and supramolecular properties can be created by incorporating the correct type of functional group partners into the oligo- and polytriazole backbone. This type of research can also advance our understanding on functional properties of such triazole-rich compounds.

New approach to oligotriazoles using a cobalt complex of propargyl azides as a synthetic component

“…3 The 1,2,3-triazole linkage has been revealed to be a promising amide bond surrogate, particularly with respect to its structure and hydrogen-bonding ability, while it shows a higher chemical and biological stability in comparison with the amide bonds. 4 Thus, it is now of great interest to elucidate the effects of replacement of an amide bond with a 1,2,3-triazole ring on the secondary structure as well as on the bioactivities in a wide range of amides.…”

“…4 Thus, it is now of great interest to elucidate the effects of replacement of an amide bond with a 1,2,3-triazole ring on the secondary structure as well as on the bioactivities in a wide range of amides. Recently, Angelo and Arora introduced a new class of oligotriazole as a peptidomimetic, named tirazolamer, in which the triazole rings and the sp 3 -hybridized carbons possessing amino acid side chains are alternately connected. They indicated that optically active trimeric and tetrameric triazolamers adopt zigzag conformations and show a potential inhibitory activity of HIV-1 protease.…”

“…Yuichi Tsukada, Kohei Yamada, and Munetaka Kunishima* R N 3 Co 2 (CO) 6 PhCOHN N N According to the recent developments of Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) as the most useful ligation process in click chemistry, 1,2 a variety of compounds with 1,4-disubstituted 1,2,3-triazole backbone have been synthesized. 3 The 1,2,3-triazole linkage has been revealed to be a promising amide bond surrogate, particularly with respect to its structure and hydrogen-bonding ability, while it shows a higher chemical and biological stability in comparison with the amide bonds.…”

“…we had expected, CPAs (2a-f) were readily prepared from the corresponding propargyl alcohols (1a-f) by Nicholas reaction using TMSN 3 and BF 3 -Et 2 O (Table 1). 9 Since 2g (R = CH 2 CH 2 SMe) possessing the side chain of methionine was found to be difficult to synthesize by the same method presumably due to the high nucleophilicity of sulfide group, it was prepared in a stepwise fashion from 1g in 61%; mesylation of the hydroxyl group 1g, nuculeophilic substitution with sodium azide, followed by complexation with Co 2 (CO) 8 (Eq 1).…”

Trimer Porphyrin Star

“…Triazole heterocycle represents non-interfering linker simply formed via so called "click" reaction -Huisgen's 1,3-diploar cycloaddition allowing for connection of independent molecular species together with accompanying interesting conformational and supramolecular features. [11][12][13] At present time only a few porphyrin dimers with 1,2,3-triazole bridge have been synthesized [14][15][16] thus the construction of "click"-connected multiporphyrin systems and particularly "click"-built porphyrin star is of special interest.…”